Monoclinic phosphorus, also called Hittorf's phosphorus, is prepared according to the prior art as follows: 1 g of white phosphorus and 30 g of lead are heated slowly in a sealed tube to 630.degree. C. and held for a short time at that temperature. The solution is then cooled at the rate of 10.degree. per day for 11 days to 520.degree. C., and cooled rapidly to room temperature thereafter. It is next electrolyzed in a solution of 2 kg of lead acetate in 8 liters of 6% acetic acid, and the phosphorus is collected in a watch glass placed under the anode. Nearly square tabular crystals, about 0.2.times.0.2.times.0.05 mm, are obtained in this way.
The structure of this prior art monoclinic phosphorus has been determined by Thurn and Krebs. The crystals comprise two layers of pentagonal tubes of phosphorus with all of the tubes parallel, and then another pair of layers of all pentagonal tube phosphorus, the tubes in the second pair of layers all being parallel, but the tubes in the second pair of layers being perpendicular to the tubes in the first pair of layers. The space group of the crystal has been determined, as well as the bond angles and bond distances. See the summary of the prior art in the section "Phosphorus" from "The Structure of the Elements" by Jerry Donahue, published in 1974.
Because of the small size of the crystals produced by means of the prior art technique, their electronic properties have not been determined.
The preparation of high purity electronic grade phosphorus according to the prior art is very complex and time consuming, thus electronic grade phosphorus is very expensive.